Friction-clutch.



s. ELLIOTT. FRICTION CLUTCH.

APPLICATION FILED MAR. 30, 1910.

1 ,O47,01 1 Patented Dec. 10, 1912.

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STERLING ELLIOTT, OF NEWTON, MASSACHUSETTS.

FRICTION-CLUTCH.

Specification of Letters Patent.

Patented Dec. 10, 1912.

Application filed March so, 1910. Serialflo. 552,287.

and has for its object to improve the construction of the driven-member to the end that the spring-arms bearing the clutchrims may be bent at points intermediate their length, whereby a thrust is exerted in the direction of the length of the arms, tending to move the clutch-rims bodily in a direction radial to the axis of the hub, as contrasted to rocking said clutch-rims,

whereby the area of contact between the clutch-rims and flange is maintained; also to arrange the clutch-rims on their supportlug-arms, so that they extend both forward and rearward of the arms, and, being thus supported intermediate their wldth, are prevented from rocking to any appreciable extent when moved in an outward direction.

by the supporting-arms; also to provide improved spring-actuated means for operating the clutch-members; and also to provide a brake for the driven-shaft adapted to be operated by said spring-actuated means with a ielding pressure. I

igure 1 is a longitudinal verticalsection of the friction-clutch embodying this invention, Fig. 2 is a cross-section of the same taken on the dotted line 22, Fig. 1, Fig. 3

is a detail-to be referred to, Fig. 4 is a side view showing modified means for moving the driven-member.

a represents a loose pulley arranged on a hollow shaft awhich constitutes the drivmemb ing-member of the clutch, said shaft being supported by suitable bearings e,' e. The

. flange ,a of said pulley has formed on its under side a conical .engagin -face, adapted to be engaged frictionally y the drivener. I

t represents the hub of the driven-memher, which is slidably arranged on said holi low shaft, and from said hub a plurality of spring-arms 12 extend in a" radial direction,

which are arranged in a conical plane, being thereby disposed diagonally with respect to the axis of the'hub. Said arms have at their, extremities curved clutch-rims b formedjwith conical engagingfaces adapted to engage the conical engaging-face of the driving-memberf \The diagonal deflection Y or arrangement of the supporting-arms b from; a perpendicular is such that they occupy a position approximately at right angles to the conical en'gaging-faces-of the clutch As here shown, the clutch-rims are extended both forward and rearward of, or in opposite directions from, the supportingarms, so that they are supported by said arms at points-intermediate their width. Said supporting-arms instead of being constructed. to move relatively to the hub by bending at their points of junction with or adjacent to the hub, and thereby swinging the clutcherims bodilyin arcs of a circle, causing them to rock as the hub is moved inward on the shaft, are here shown as recessed atb at their opposite sides, at points intermediate their length, to purposely form points of greatest weakness at such intermediate points, which, it will be observed, are

quite remote from the hub, so that said arms will bend at such intermediate points and cause bodily movements of the rims in. directions radial to the axis of the hub. Such movements are of course slight, yet appreciable, and suflicient to enable the entire. engaging-faces of the clutch-rims to continue to engage the flange of the driving-member; Whereas, if said rims are permitted or caused to move in arcs of a circle, or to rock,

the angles'of their engaging-faces cone-- spondin ly change with relation to the engagingace of the flange of the drivinginember, and the areas of the engaging-surfaces are correspondingly reducedf I I By my invention when ;the hub is moved inward on the shaft the spring-arms and clutch-rims remain in their normal posi tionsuntilthe rims first' engage the flange of the driving-member; continues to move inward, said rims will be moved'inward farther only a slight dis tance, while the spring-arms will be bent at points intermediate their length, and, acting as toggles; will exert upon the clutch-rims,

I at points {intermediate their width, thrusts 'then, as the hubjiio ,2

in the direction of the length of the arms, causing a bodily movement of said clutchrims in a direction radial to the axis of the hub, which is slight, yet appreciable, to obtain the necessary friction-grip.

For the accom lishment of the results which I obtain it is necessary thatv the supporting-arms be disposed at approximately right angles to the conical engaging-faces of the clutch-rims, and that said arms be constructed with points ofgreatest weakness intermediate their length and sufiiciently re mote from the hub to bend at such points and act as toggles, and it is very desirable that the clutch-rims be supported at points intermediate their width. As here shown the rims and supporting-arms therefor and the hub are integrally formed, and such integral formation is preferred. The recesses 6 formed in the opposite sides of the spring supporting-arms, may be of any desired shape, but the location of said recesses is of the greatest importance, as it is necessary that they be formed'remote from the hub to enable the arms to bend at points intermediate their length to cause a bodily movement of the rims in a direction radial to the axis of the hub.

As shown in Fig. 1, a key a is arranged diametrically with respect to the hub b, in radial slots therein, which extends through longitudinal slots in the hollowshaft a, and

through a hole in a rod (1, arranged in said shaft, and said key is fixed at its ends to the hub by pins 0'. The rod 03 is moved longi: tudinally in the hollow shaft (1 for the purpose of moving the driven-member into and out of engagement with the-driving-memher. For the accomplishment of this result said rod is encircled by a spring (1 bearing at one end against a shoulder on the rod.

' and at the other end against a cap d, which is screwed on to the end of the shaft, the tendency of said spring being to move the rod inward and thrust the driven-member into engagement with the driving-member,

when permitted to act. Said rod has fixed to it a collar (i which may be engaged by the bifurcated end (i of a lever 03 which is employed for moving said rod outward .against the stress of said spring. The hollow shaft has a headed screw 9, or it may be a collar, at its end, which extends over cap movin the hollow shaft longitudina ly, and, a though such movement is slight, yet it is suflicient to move the flange 71, into engagement with the fiat-faced bearing 6 and thereby check rotation of the shaft. Said flange serves as the movable member of a brake, and the flat-faced-bearin e as the stationary member thereof. Sa1d stationary member, however, may be otherwise constructed.

The force employed to move the movable brake-member into engagement with the stationa cans by the sprin d when the rod (2 is moved outward. en the lever d is moved toward the left, Fig. 1, from the dotted to the full line position, the rod (1 is moved inward by the spring, and the hollow shaft is permitted to move longitudinally, or may be caused to move longitudinally by the clutch-members moving the loose pulley against the headed-screw g such longitudinal movement of the shaft, however, being slight yet sufficient to disengage the brake-members.

Any other means may be employed for moving the driven-member, as, for example, referring to Fig; 4, the hub may be provided with a circumferential groove which is engaged by an operating-lever f.

I claim:

1. In a clutch, a driving-member having a flange with an under conical engagingface, and a driven-member consisting of a hub having a plurality of spring-arms extended radially from it, arranged in a conical plane and having curved clutch-rims at their extremities, which are formed with conical engaging-faces arranged at right angles to the plane of the arms, said arms having recesses at opposite sides, at points intermediate their length, permitting them to bend at such intermediate points when subjected to end thrust, substantially as described.

2. In a clutch, a driving-member having a flange with an under conical engaging-- face, and a driven-member consisting of a hub having a plurality of spring-arms extended radially from it, arranged in a conical plane and having curved clutch-rims at their extremities, which extend forward and brake-member is yielding, being rearward of the arms and which are formed conical engaging-faces arranged at right angles'to the plane of the arms, said arms name to this specification, in the presence of having recesses at opposite sides, at points two subscribing witnesses.

intermediate their length permitting them to bend at such intermediate points when STERLING'ELLIOTT' 5 subjected to end thrust, substantially as de- Witnesses:

- scribed. B. J. Nome,

In testimony whereof, I have signed my H. B. DAVIS. 

